Lewis & Short

2. calcĭtro, ōnis, m. [1. calcitro].

  1. I. One who strikes with his heels, a kicker: equus mordax, calcitro, Varr. ap. Non. p. 45, 2 (Sat. Men. 81, 3).
  2. II. Of men, a boisterous fellow, a blusterer, Plaut. As. 2, 3, 11.